package com.zh.netty.websocket;

import com.zh.netty.heartbeat.MyServerHandler;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.stream.ChunkedWriteHandler;
import io.netty.handler.timeout.IdleStateHandler;

import java.util.concurrent.TimeUnit;

/**
 * @Description: websocket 服务器端
 * @ClassName MyWebSocketServer
 * @date: 2021.03.09 14:32
 * @Author: zhanghang
 */
public class MyWebSocketServer {
    public static void main(String[] args) throws Exception{
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup(8);
        try {
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(bossGroup,workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .handler(new LoggingHandler(LogLevel.INFO)) // 添加日志处理器
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline pipeline = ch.pipeline();
                           // 因为基于http 协议，所以使用http的编码和解码器
                            pipeline.addLast(new HttpServerCodec());
                            // 是以块的方式写，添加ChunkedWriteHandler 处理器
                            pipeline.addLast(new ChunkedWriteHandler());
                            /**
                             *说明：
                             * 1. http数据在传输过程中是分段，HttpObjectAggregator,就是可以将多个段聚合
                             * 2. 这就是为什么，当浏览器发送大量数据时，就会发出多次http请求
                             */
                            pipeline.addLast(new HttpObjectAggregator(8192));

                            /**
                             * 说明：
                             * 1. 对应websocket, 它的数据是以 帧(frame)的方式传递
                             * 2. 可以看到WebSocketFrame 下面有六个子类
                             * 3. 浏览器请求时 ws://localhost:7000/hello 表示请求的uri
                             * 4. WebSocketServerProtocolHandler 核心功能是将http协议升级为 ws协议，保持长链接
                             */
                            pipeline.addLast(new WebSocketServerProtocolHandler("/hello"));

                            // 自定义的handler,处理业务逻辑
                            pipeline.addLast(new MyTextWebSocketFrameHandler());
                        }
                    });
            ChannelFuture channelFuture = bootstrap.bind(7000).sync();
            channelFuture.channel().closeFuture().sync();
        }finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}
